Optimal Error Correcting Delivery Scheme for an Optimal Coded Caching Scheme with Small Buffers

Optimal delivery scheme for coded caching problems with small buffer sizes and the number of users no less than the amount of files in the server was proposed by Chen, Fan and Letaief [“Fundamental limits of caching: improved bounds for users with small buffers,” IET Communications, 2016]. This scheme is referred to as the CFL scheme. In this paper, an extension to the coded caching scheme where the link between the server and the users is error prone, is considered. The delivery phase is error prone and the placement phase is considered to be error free. The closed form expressions for average rate and peak rate of error correcting delivery scheme are found for CFL prefetching scheme using techniques from index coding. For a given demand, the delivery phase of a coded caching problem becomes an index coding problem. Using results from error correcting index coding, an optimal linear error correcting delivery scheme for caching problems employing CFL prefetching is proposed.